According to folklore, fairy rings are magical circles in which witches and faeries meet to sing and dance at night. Fairies dance in circles and when a human is lured inside he can’t escape unless he is pulled out of the circle by a human chain. Inside time is different and what seems like a couple minutes could actually be several days. 

Fairy rings is also the name for the circles of inedible mushrooms that grow in grassy areas in North America, Europe, and Britain. Also called hag tracks in Britain, they are believed to be created by witches' dancing feet.